Abstract: A movable electrical contactor having a surface thereof in slidable contact with a mating conductor, the surface being coated with a composite material in which particles of graphite (C) are dispersed in a matrix of silver (Ag). The coating film is formed by electric plating using a plating liquid of metal silver in the range of 2-100 g/l in concentration, potassium cyanide in the range of 2-250 g/l, potassium hydroxide in the range of 0.5-15 g/l, graphite powder in the range of 1-55 g/l, and a dispersant for dispersing graphite powder into plating liquid in the range of 10-2000 ppm.

Abstract: A circuit breaker in which a movable contactor is held by a holder of electrically insulating material which is rotatably supported through a switching shaft on a casing. The movable contactor is driven by a switching mechanism to be swung about the switching shaft together with the holder to perform a switching operation. The movable contactor is slidably electrically connected to a connecting conductor secured to the casing.

Abstract: A compact, high capacity circuit breaker includes two breaking portions mounted in a single casing, with movable contacts for each portion disposed in series with one another and supported by a common switching shaft. Both portions of the breaker are tripped by either an overcurrent condition or manual operation, and the positioning of the common switching shaft maintains both breaking portions in the open state.

Abstract: A contactor device for a circuit breaker includes a stationary contactor having a stationary contact, and a stationary conductor secured with the stationary contact and constituting an electricity path extending from an external terminal to the stationary contact, and a movable contactor having a movable contact movable to detachably touch the stationary contact, and a movable conductor secured with the movable contact and constituting an electricity path extending from the movable contact to another external terminal.

Abstract: A contactor device of a circuit breaker has a movable contactor to be raised or opened upon the occurrence of a short circuit current. One end portion of the movable contactor is bifurcated to form parallel claw members that engage a rotatable trip latch. When the movable contactor is raised due to a magnetic repelling force generated in the movable contactor and a fixed contactor during a short-circuit condition, the claw portions of the movable contactor are deformed due to a magnetic attractive force and are disengaged from the trip latch. The rotation of the movable contactor is restricted and it returns to the original positional relationship in which the claw members are engaged with the trip latch.

Abstract: A limiting-current type contactor apparatus for providing stable current-limiting breaking properties with less reduction of the breaking speed due to magnetic repulsion force is provided with a movable contactor arm supported by a contactor support fixed to a switching shaft and a fixed contactor. The fixed contactor has a first conductor portion and a shaft for pivotally mounting the movable contactor. The movable contactor has a second conductor portion spaced opposite and apart from the first conductor portion, thereby forming an arcuate gap of uniform and small width between the first and second conductor portions and concentric with the shaft. A flexible conductor is connected between the first and second conductor portions for reversing the direction of current flow between first conductor portion and the movable contactor arm.

Abstract: Individual movable contactors of a circuit breaker are made up of a pair of conductors. The first conductor has one end bifurcated to form a pair of legs separated by a slit. At the open end each leg has a curved inner portion the opposed curved portions of the two legs defining a receptor space which is substantially circular in cross section. The second conductor has one end whose cross section is substantially circular and which fits within the receptor space and makes a good slidable contact therewith, and the other end which supports the main contact. Provision is made for rotating the second conductor about its circular end for opening or closing connection to the main contact.

Abstract: In the particular embodiments described in the specification, an attachment for a circuit breaker is mounted in an outer box which can be inserted into a recess in the cover of the circuit breaker case. The outer box has two guide projections which are received in channels in the cover and two projecting portions which interlock with corresponding portions on the circuit breaker housing.

Abstract: A circuit breaker for high-speed current-limiting breaking of a three-phase current in the event of a short-circuit condition. The breaker has three pairs of fixed and movable contactors, the latter being arranged for pivoting movement on a common shaft. The center movable contactor is biased against an opposing holder, such that in the event of a short-circuit, the bias is overcome and the movable contactors separate in unison from the fixed contactors.

Abstract: A circuit breaker having stationary contactors provided for all of the poles thereof. Movable contactors are provided for all of the poles in correspondence to the stationary contactors. Stationary contacts are provided on the end portions of stationary contactors and movable contacts are disposed on the end portions of the movable contactors. The movable contactors are movable from the stationary contactors by electromagnetic force to open respective circuits before the circuit breaker is opened by an overcurrent tripping device when large current such as short-circuit current flows. Holders adapted to hold the movable contactors of all of the poles are mounted on a common rotatable insulating rod, one of the holders being provided with a latch which is turnable around a rod provided on the holder. A slot is normally engaged with the latch, and when disengaged from the latch, a rod can be turned by the holder.